The continuous population registers of La Hulpe will provide the core of the data analyzed to investigate the demographic transition between 1846 and 1880 at the micro-level of households and couples. Additional demographic data available include the register of births, deaths and marriages; but also registers of stillbirths and migrations. These data will be used to reconstitute families and household cycles. The socio-economic information of the time includes data on income (taxation), land tenure (cadastre) and inheritance (notarial records). We shall attempt to identify groups of contraceptors, by comparing various indices of fertility to a base line prior to fertility decline. Contraceptive use and fertility trends will be related with economic, social and cultural characteristics recorded for these people, as well as with demographic characteristics (e.g. mortality, nuptiality) and with identifiable pressures in the household cycle. The emphasis will be on longitudinal and dynamic aspects.